This invention relates to a water-cooled, multi-cylinder internal combustion engine comprising a cylinder block, a cylinder head, and a cooling jacking, all cast in one piece, the cylinder head comprises, for each cylinder of the cylinder block and on one longitudinal side thereof, an intake and exhaust duct as well as valve guide sockets and on the other longitudinal side a mounting socket for an injection nozzle or sparking plug, forming a connection between the end wall of the cylinder and the cooling jacket.